A 21-year-old facing jail time for assaulting his friend's father blew his case after posting a public message to a friend on Facebook telling him he thinks he'll "get away with it."

Michael Ruse and Terry Reeve — both from the Hampshire suburb of Leigh Park — were charged with beating up Reeve's father with a baseball bat and a baton.

While awaiting a decision in his trial, Ruse wrote a reply to a friend's Facebook message asking how it was going. "Yeah I think I get away with it tbh," Ruse said. An anonymous observer of the exchange printed out its contents and brought them to the court's attention.

Ruse promptly changed his plea to guilty.

"You pleaded guilty part way through the trial only really because you were stupid enough to put on Facebook what amounted to a full confession," said Judge Ian Pearson, who offered Ruse no quarter in return, noting, "your stupidity really is not much mitigation."

Ruse's lawyer, Russell Pyne, had no choice but to side with the judge. "He needs help with regards to thinking skills," Pyne told the court.

Ruse was ultimately sentenced to 46 weeks in prison, but the inability to learn his lesson leaves much to be desired. After sentencing, Ruse returned to Facebook to chew out the judge, calling him "stuck up."